Secondary aminoalcohol-boric acid reaction product and production thereof



Feb. 25, 1969 D. scHusrER 3,429,909

SECONDARY AMINOALCOHOL-BORIC ACID REACTION PRODUCT I AND PRODUCTIONTHEREOF 1 1 I 1 l I I I I l T I l l l I I I l l I I l I I I/234557di/0///2/3/4/5/6/7/.5/y2a2/2223w2525272d2y @ff/az, Na/ML FIG.I

IN V EN T 0R. /Er/P/r/f 5a/afrik? BYUM/Lgr Feb. 25, 1969 D. scHusTr-:R3,429,909

SECQNDARY AMINOALCOHL'BORIC ACID REACTION PRODUCT AND PRODUCTION THEREOFFiled April 25, 1966 Sheet Gowuom umm Sheet I 3 of 5 Feb. 25, 1969 D.SCHUSTER SECONDARY AMINOALCOHOD-DORIC ACID REACTION PRODUCT ANDPRODUCTION THEREOF Filed April 25, 196e United States Patent O 2 ClaimsABSTRACT F THE DISCLOSURE Boronand nitrogen-containing reaction productis obtained by reacting boric acid and a secondary aminoalcohol, andthen reacting the resulting product with a carboxylic acid, underspecified conditions. Products are bacteriocidal, non-corrosive andbiodegradable, and can be dissolved, dispersed or emulsied in water.

The present application is a continuation-in-part of my priorapplication Serial Number 413,366, filed November 23, 1964, nowabandoned, and entitled Rust Preventing, Wetting and Emulsifying Agent.

The present invention relates to compositions, and to a process for themanufacturing of such substances, which are bacteriocidal,non-corrosive, act as wetting agents, and are bio-degradable upondilution with water. The new compositions are particularly useful ascooling and lubricating agents, for example, as cutting fluids in themetal working industry, but also have desirable cleaning properties andcan thus be used as detergent concentrates.

Recently, efforts have been made to improve the working of metal,particularly metal cutting and metal forming, by better cooling andlubrication. Synthetic substances, based on water as a coolant havedecided advantages over hydrocarbon or oil derivative products. Thecooling properties of water are far superior to those of other products,particularly when the surface tension of the water is decreased by theuse of wetting agents. Water alone is however not useful due to itscorrosive action, particularly when known wetting agents have beenadded, as well as due to its lack of lubricating effectiveness.

Various proposals have been made to develop cutting uids based on waterby use of additives. For example, soaps added to water have been used,particularly soaps which are derived from amino alcohols, with additivesof higher sulfonated, or unsulfonated fatty acids or naphthenic acids,or from carboxylic acids, obtained from the oxidation of hydrocarbons.

The use of ethanolamine based soaps is particularly advantageousbecause, in a watery solution, a pH value of above 9 is readilyobtainable, and thus they do have some corrosion inhibiting effect. Thecorrosion inhibiting effect can be increased by adding other acids orsalts, in order to increase the buffering action. Additives described inthe literature include, for example, alkylsulfoneamidocarboxylic acid,and its salts; and boric acid and its salts.

The corrosion resistant effect of such aqueous cooling and lubricatingsubstances is further improved by adding sodium nitrite which isrecommended as an additive for almost all aqueous products.Unfortunately, sodium nitrite is extremely poisonous. In actualpractice, sodium 3,429,909 Patented Feb. 25, 1969 ice nitrite is usuallyadded in quantities of from l to l0 percent to the concentrates used forcutting liuids. From the point of view of the health of the worker atthe machine, in which the fluids are used, this is an undesirableadditive. The lethal dosage for an adult human is only four grams ofsodium nitrite. Lethal poisonings in adults are observed primarily inconnection with food and food preservation; nevertheless, cutting uidsused on the machines do leave a spray or a mist from time to time whichare inhaled by the machine operators and may cause anaemia and low bloodpressure, as well as damage to the blood circulatory system, and even insmall doses may cause or contribute to liver damage due to the formationof nitro compounds.

Known substances, in many variations and in combinations with bulferingagents and sodium nitrite as a corrosion inhibiting agent, havesubstantial disadvantages, entirely apart from the poisonous aspect ofthe sodium nitrite itself. One of these disadvantages is that fattyacids used in such soaps form salts which are difficult to dissolve incombination with alkali metals, and may cause precipitates whicheventually cloud the solutions or result in scum; at its worst, they mayinterfere with the disposition of the colloidal solutions themselves.Therefore, and in order to stabilize such precipitates, variousproposals have been made to stabilize such aqueous solutions. One ofsuch proposals is to add a non-ion forming emulsifier, in order todisperse the difcultly soluble calcium salts. These non-ionic emulsiersor wetting agents are, chemically, condensation products of alkyloxideswith various organic substances, for example polyetheralcohols, fattyalcohol polyglycolethers, fatty acid amido polyglycolethers or fattyacid polyglycolesters. Typical examples are: octylphenylpolyetheralcoholmixed in with the above-identified substances; a non-ion formingcondensation product derived from amines with ethylene oxide; and amonobutylether of a condensation product of an alkyloxide withethanolamine.

The above described mixtures have good wetting and dispersion propertiesand also impart good corrosion resistance. Further additives are used inorder to increase the lubricating effectiveness to provide forbacteriocidal and fungicidal effect and to prevent foaming. Non-aromaticoil distillates are often added in order to improve the lubricatingeffectiveness. In order to provide for bacteriocidal and fungicidalproperties, and particularly in order to suppress the growth ofanaerobic bacteria, additives consisting of phenol, cresol, or triazinederivatives are used, or highly antiseptic chlorine compounds. Yet,bacteriocidal and fungicidal additives at times contribute todermatological disease. Some investigators, active in industrialmedicine, regard these additives as a most usual cause of industrialdermatosis. Entirely apart from the susceptibility of several operatorsto these additives, they are undesirable because they inhibit the growthof bacteria not only in the material itself, but also in settling tanksand in the streams and rivers to which industrial wastes are often,unfortunately, conducted, since they prevent biological degradation andcause pollution.

The compositions according to the present invention are inherently notpoisonous. Thus, they have the property of bacteriocidal and fungicidaleffect in the concentrations used in the metal working industry; thesebacteriocidal and fungicidal effects are lost, however, when thecompositions are diluted to the extent customary in a settling tank.Upon such substantial dilution, they become biologically degradalble.Further, the compositions of the present invention have insecticidal andinsect repellent effects so that not only the agents causingdecomposition and dermatosis are inhibited, but the carriers ofbacteria, that is primarily flies, are not found in the environmentwhere the new compositions are used. Nevertheless, the compositions arenon-toxic to humans and do not cause skin irritations.

It is an object of the present invention to provide compositions whichare bacteriocidal and non-corrosive and which have the desirablelubricating properties of oilbased cutting uids while retaining thedesirable cooling properties of Water-based cutting fluids, without anyof the disadvantages of either fluid.

It is further an object of the present invention to provide cuttingfluids which are medically acceptable to the operator of the machine onwhich the uids are used, that is fluids which are bacteriostatic,fungicidal and yet non-poisonous. It is a further object of the presentinvention to provide a metal working fluid which is Ibiologicallydegradable so that it will not present disposal problems but may bedischarged into public rivers and streams without causing pollution orendangering fish or plant life.

It is yet another object of the present invention to providecompositions which have detergent and cleaning properties, are readilysoluble, bacterie-static, and yet biologically degradable whensufliciently diluted.

Briefly, in accordance with the present invention, at least two molarproportions of a secondary aminoalcohol are reacted with one molarproportion of boric acid (H3BO3) or are -analog thereof (preferably 3:1to 5:1) at a temperature varying from about 130 C.; water formed in thereaction is removed from the resulting reaction system, whereby aboronand nitrogen-containing reaction product is obtained. This reactionproduct can then be reacted with a carboxylic -acid at a temperature offrom about 150 C. to about 230 C., With water being again removed fromthe reaction system, whereby a -bacteriocidal, non-corrosive, boronandnitrogen-containing reaction product is obtained. The latter reactionproduct is also a wetting agent and is characterized by the propcrty ofbeing biodegradable when diluted with a substantial quantity of water.

The yreaction of the aminoalcohol with the boric acid may be done in thepresence of glycols in the range of from 0.1 or less, to about molarproportions of the glycol for each molar proportion of aminoalcohol. Theproduct thus obtained is less viscous, easier to dilute with water to aworking cutting fluid solution and, by suit-able choice of the glycol,provides smoother cut surfaces when used as a cutting uid in a machinetool operation.

As indicated, molar proportions of secondary aminoalcohol -and boricacid and reaction temperatures are important factors in the productionof the desired reaction products. The exact composition of the saidproducts is not fully clear at this time, such that exact chemicalformulae/ cannot be ascribed to them. However, it appears that -bycareful control of reaction temperature within the ranges given above,and by using certain acids, it is possible to form piperazine compoundsand to isolate the same from the remainder of the reaction products.This represents a further embodiment of the present invention. Reactiontemperatures are controlled to from `about 160 C. to about 230 C., andsaturated or unsaturated carboxylic acids having a chain length of C12to C22 are used in the reaction of aminoalcohol, preferablydiethanolamine, and boric acid. This is illustrated below in theexamples.

Water is formed in the initial reaction stage between a secondaryaminoalcohol and boric acid. For each mol of boron compound used, atleast one and not more than three mols of water are formed. And water isalso formed during the second reaction stage in which Ia carboxylic acidparticipated. It is a characteristic of this second stage that there isformed at least one mol of water for each mol of fatty acid charged.

As contemplated herein, analogs of boric acid include: HBO2, H2B4O7 andB203, as Well as their corresponding salts, esters and halogencompounds. Preferred, however, is boric acid (H2BO3).

Aminoalcohols used herein are represented by the general formula whereinR and R' are either the same or different bivalent aliphatic groups(-CH; CH2-CHF, ete), which may have one or more side chains orsubstituents therein. Preferably, the length of the chains R and R' aresimilar and contain from 1-6 carbon atoms. Typical compounds arediethanolamine and diisopropanolamine. Particularly preferred isdiethanolamine.

It is also contemplated that a tertiary aminoalcohol, astriethanolimine, can also be used together with a secondaryaminoalcohol. In all such instances, the secondary compound is used ingreater quantity than the tertiary compound.

Carboxylic acids of a wide variety can be used in forming reactionproducts coming within the framework of this invention. The acids can besaturated or unsaturated and contain at least about 8, preferably fromabout 12 to about 22, carbon atoms per molecule. Typical acids arelauric, myristic, palmitic, stearic, oleic, and all oil acids,naphthenic acids and phthalic acid. Generally, from about 0.5 to about 3molar proportions of carboxylic acid are used per molar proportion ofboric acid.

The invention is illustrated by the following examples.

Example 1 Production of an intermediate reaction product containingboron and nitrogen is illustrated by this example.

945 g. (9 mols) of di-beta-hydroxyethylamine (diethanolamine) are mixedat a temperature of about C. with 122 g. (2 mols) of pulverized or`granular boric acid (H3BO3) in a retort of about 2 liter capacity. Theretort is connected with a descending cooler and provided with anelectrical mixer. Mixing is continued until the entire boric acid isdissolved. Thereafter, under strong heating, a condensation reaction isstarted, which begins at a temperature of about C., at which thereaction mixture begins to boil and water is split off. The water ofreaction is collected in the descending cooler in a measuring vessel.With a period of about 45 minutes to one hour, the temperature of thereaction mixture is raised to a temperature of about 230 C., and about100 to 108 ml. of water is formed and is distilled off. This correspondsto approximately 6 moles of reaction water; that is, approximately 3mols of water are obtained per mol of boric acid.

Thereafter, the reaction mixture is subjected to vacuum distillation inorder to determine how much di-beta-hydroxy-ethylamine are obtained,having a boiling point of about -165 C. This indicates that thecondensation reaction according to the example provides a composition inwhich one mol boric acid has reacted with two mols ofdi-beta-hydroxyethylamine.

The reaction product obtained after the vacuum distillation is a clear,honey-colored substance which, as it cools, becomes glassy. If thissubstance is heated to the point of just melting, and stirred with aglass rod, the crystalline form of the reaction product is obtained.

The product showed the following analytical composition (carbon andhydrogen determination according to Liebig):

Carbon, 42.1-42.5 percent,

Hydrogen, 8.8-9 percent,

Nitrogen, 11.7-12 percent (Dumas); 12.2 percent (Kjeldahl),

IBoron, 4.5-4.8 percent (determined as boric acid after saponiticationwith hot, fuming hydrochloric acid).

Example 2 1260 g. (12 mols) of di-beta-hydroxyethylamine(diethanolamine) are mixed with 244 g. (4 mols) of boric acid in powderor granular form in a 2.5 liter retort, provided with a heating jacket,a distillation head and a descending cooler, and an electrical stirringmechanism. Mixing temperature is about 100 C. and mixing is continueduntil all of the boric acid is dissolved. Thereafter, the condensationreaction is started under substantial heating as in Example 1, whichreaction begins at about 130 C. Water is split off. The Water ofreaction is condensed over the descending cooler and collected in ameasuring vessel. As before, in about 45 minutes to one hour thereaction temperature is raised to about 230 C., and about 210 to 216 ml.of Water are split and distilled off. Thereafter, heating isdiscontinued and the reaction mixture is permitted to cool to atemperature of about 160 C. Heating is commenced again and at the sametime 280 g. of tall oil (a mixture of fatty acids) at a temperature of160 C. are added to the reaction mixture, for example through a separatetube. Mixing is started rapidly in order to provide for quickintermingling of the substances in the retort. After addition of thetall oil, the inlet through which it was added is closed. When themixture reaches 180 C., the second step of the condensation reactionstarts. Within a period of about two hours, 65 to 72 m1. of water aresplit off. The temperature should not exceed 230 to 240 C.

The thus obtained reaction mixture is permitted to cool to a temperatureof about 80 to 120 C., and is then poured into a vessel containing 1350g. of distilled water. The reaction mixture and the water are mixed anda thick honey-like liquid, similar to an emulsion and having a pleasantsmell, similar to esters, is obtained. A nonaromatic hydrocarbonfraction, in accordance with the 4following specilication, is added tothis emulsion under constant stirring, until a completely clear viscous,yellow, pleasantly fruity smelling liquid is obtained. For completeclearing of the solution which is initially similar to an emulsion, 80to 160 g. of the hydrocarbon are necessary.

Specification of the hydrocarbon fraction is: specific gravity, C.,0.805; boiling point: 244-332D C.; refractive index, 1445; ash point,106 C.; iodine number, 0.03; aniline point, 91 C.

Instead of this hydrocarbon fraction, other mineral oil fractions,glycols, polyglycols, fatty acid amides, polyesters, polyethers,silicones, or other substances which are capable of changing theemulsion to a clear liquid with an addition of at the most percent ofsuch material, may be used.

The concentrate according to Example 2 is completely soluble in anyproportion with water, remains clear, hardly foams, and does not formprecipitates with hard water. It is an ideal cooling-lubricant-anddetergent concentrate which can be used, diluted in water, up to 0.05percent.

Example 3 First reaction step: the rst reaction step is carried out asin Examples 1 and 2, reacting: 630 g. diethanolamine (6 mols) and 122 g.boric acid, H3BO3 (2 mols); with formation of 108 g. water (6 mols).

Second reaction step: the second reaction step is carried out as inExample 2, lauric acid (200 g.; l mol) is added. Water of reaction splitoft" comprised 54 g. (3 mols).

The reaction product is soluble in water, is clear, and has strongwetting properties. Preferably it is thinned in a proportion of about1:1 with distilled water and forms a clear, water-soluble, cooling,lubricating and detergent concentrate. In order to improve the bufferingaction, two percent of the hydrocarbon described in Example 2, or

6 an organic or inorganic acid with a dissociation constant of less than5 10-4 can be added.

Example 4 First reaction step: as in Example 3.

Second reaction step: similar to Example 3, however, utilizing 288 g. ofmyristic acid, during 20 minutes and at a temperature of 225 C. 58 g. ofWater (3.2 mols) are condensed out.

The reaction product thus obtained is soapy and solid. When heated andthinned with distilled water in the proportion of 1:1, it is a stableemulsion which can be further diluted with water. The product, dilutedwith water 1:1, has good cooling, lubricating, and detergent properties,and good corrosion inhibiting effects.

A clear, water soluble product, can be lmade by adding (in parts byweight): 90 parts of the product diluted 1:1 in the above Example 4; 25parts oil and 10 parts fatty acid polydialkylamide.

Example 5 First reaction step: as in Example 3.

Second reaction step: addition of 256 g. (l mol) of palmitic acid at 200C., within thirty minutes; and condensing otf 58 g. (3.2 mols) water.

The product has a soapy character, and is soluble in water up to C.giving a clear solution. At further cooling, the substance becomes astable pasty emulsion, which can be diluted further as a cooling,lubricating or detergent substance.

In order to make the product easier to handle, a stock solution thinnedwith water, 1:1, may be mixed with 70 parts (by weight) of oil.

Example 6 Step l: as in Example 3.

Step 2: starting mixture-300 g. of a mixture of saturated CM-Cgzcarboxylic acids (l0 parts). To the starting mixture are added 53 partsof saturated C18 carboxylic acid and 35 parts of saturated C20-C22carboxylic acid, at 220 C. during 50 minutes, and 67 g. (3.7 mols) ofwater are condensed off.

The reaction product is soapy, is soluble up to 80 C. in a 1:1proportion in Water forming a clear solution. If cooled further, astable pasty emulsion results, which can be diluted with Water to form acooling, lubricating or detergent substance.

Example 7 Reaction step 1: as in Example 3.

Reaction step 2: 280 g. (l mol) of puried oleic acid is added at 220 C.in a period of 25 minutes. 50 g. of Water (2.8 mols) are condensed off.

The reaction product, when solidifying, becomes a honey-like substancewhich, when diluted with distilled water in a proportion of 1:1, forms aconcentrate for cooling, lubricating, and detergent use, and can befurther diluted with water in any proportion.

Example 8 Reaction step l: as in Example 2.

Reaction step 2: similar to Example 2; however, instead of tall oil, 280g. (l mol) of purified oleic acid is added during a period of 60 minutesat 200 C. and 94 g. (5.2 mols) of water are formed and removed.

The above product is a particularly useful concentrate for cooling,lubricating and cleaning use, when diluted 1:1 with water. Ten percentof a hydrocarbon fraction, as described in Example 2, may be added.

Example 9 630 g. (6 mols) diethanolamine are mixed with 180 g. (3 mols)boric acid, at approximately 100 C., and then 420 g. (approximately 1.5mols) of tall oil, mixed fatty acids, are added.

The reaction between the diethanolamine and the boric acid starts at 130C. While adding heat, the temperature is driven during a period of about30 minutes, to 220 C.; 192 g. (10.6 mols) of water are condensed off. Inanother vessel, a hot mixture of 315 g. (3 mols) of diethanolamine and300 g. (2 mols) of triethanolamine, at a temperature of 220 C., is addedto the first reaction product. Reaction is continued for about 30minutes, and 70 g. (3.9 mols) of water are split off.

The reaction product is dissolved in distilled water in a proportion of1:1 and forms, either in its pure form or if mixed with a hydrocarbonfraction, according to Example 2, an excellent, lubricating anddetergent concentrate.

As mentioned above, one embodiment of the invention involves preparationof reaction products, the complete composition of which is not known butwhich contain piperazine compounds. Careful control of reactiontemperature and inclusion of a carboxylic acid in the reaction ofaminoalcohol and boric acid makes this possible. This feature isillustrated below in Examples and 11.

Example 10 840 g. (8 mols) diethanolamine are mixed with 247 g. (4 mols)of boric acid, at approximately 100 C. 560 g. (approximately 2 mols) oftall oil are added. The resulting mixture is carefully heated to atemperature of about 135 C. Heating is then slowed, and controlled suchthat the mixture reaches a temperature of 150 C. in approximately 30minutes. Thereafter, the mixture is heated substantially so that itreaches a temperature of 230 C. within a further period of about 60minutes. 310 g. (17.3 mols) of water are condensed out.

The reaction product is soluble in water in a proportion of 1:1 andforms an excellent cooling, lubricating and detergent concentrate.Isolation of 1,4-di-beta-hydroxyethylpiperazine from the reactionproduct, by repeated recrystalizing from methoxy-hexanol (4-methoxy-4-methyl-pentanol-2) can be done, to obtain it in its pure form.

Example 11 50 g. of the pure, undissolved reaction product of Example 10are digested with 200 g. methoxyhexanol at 100 C. for 15 minutes and aredecanted off while hot from the undissolved resinous residue. The hotsolution is permitted to cool, and a sticky mass is separated out whichcannot be filtered. After 24 hours, the remainder of the solution ispoured off, and is reduced to about half volume in vacuum. Double theamount of benzene ether is added; after about 2 hours the layer formingon the bottom, and the solvent are decanted off, and the first,contaminated crystalline fraction is obtained. By recrystallizaton itcan be purified. From the top layer, a very pure fraction is obtained.About 6 g. of the material, having a melting point of 130 C. areobtained. Analysis and infra-red spectrum determination conrm theidentity of the product as 1,4-di-beta-hydroxyethylpiperazine.

Example 12 Using apparatus as described in Example 2: 840 grams (8 mols)diethanolamine are dissolved at about 100 C. in 244 grams (4 mols) boricacid, until a clear solution is obtained.

Thereafter, 240 grams (2 mols) ethyleneglycol monoethylether is addedand the resulting reaction mixture is heated while being stirred well.This reaction starts at about 130 C. while water is being split off. Thesplit-off water is collected in a descending measuring cooler vessel.After about 45 minutes to an hour, the reaction temperature is raised toS-210 C., until a total amount of 210- 216 ml. water is split off.Without interrupting the heating, 280 grams (1 mol) fatty acid, e.g.oleic acid, at a temperature of about 130 C. are added, for examplethrough a tube; (it is observed that the temperature in the reactionvessel will fall to about 190 C.). As stated, heating is continued andthe reaction with the fatty acid will start at about 195 C.; in a periodof about 20 minutes, 54 ml. (3 mols) water are condensed off, and aiinal temperature of 220 C. is reached.

The product thus obtained is honey yellow, pours easily and may be usedas a ready, Water soluble, clear, cooling and lubricating substance.

To provide a cutting fluid concentrate, fifty parts of the productobtained in accordance with Example 12 are mixed with parts water and 5parts of hydrocarbon, as described above in connection with Example 2.The product has excellent rust-inhibiting characteristics and all theother characteristics heretofore described.

Example 13 Starting ingredients and steps are as above in Example 12until the point at which, at 205 C., 216 m1. water are split off (samereaction conditions and quantities of diethanolamine, boric acid, anddiethyleneglycol monoethylether) Then, one mol of hot triethanolamine isadded and thereafter at least one mol water is condensed off. As abovedescribed, one mol (280 g.) of oleic acid is added and 3 mols (54 ml.)water are condensed out. Final temperature is approximately 200 C. Theproduct obtained is thick and honey-like, and is an excellent emulsier.

Example for a cutting fluid concentrate: parts of the product inaccordance with Example 13 are mixed with 20 parts of spindle oil and 30parts of water. The resulting product is a clear, easily mobile liquidwhich easily dilutes clear in water to form working solutions and hasexcellent rust-inhibiting properties.

Example 14 Similar to Example 13, but instead of one mol oftriethanolamine, one mol (6l g.) of monoethanolamine is added. All otherconditions are the same, even the water being split off and the naltemperature.

The product is slightly opaque when dissolved in water, and can be usedas such as a cutting fluid.

Example 15 A mixture of diethanolamine and boric acid, in the samequantities as in Example l2; thereafter, 360 grams (3 mols) ofdiethyleneglycol monoethylether is added. The mixture is heated to about205 C., and 216 ml. water are distilled olf. Without interrupting theheating, as described, 280 grams of oleic acid (l mol) are added, heatedin about 30 minutes to 220 C. and kept at that temperature for about 30minutes. 4 mols of water (72 ml.) are distilled off.

The product without addition of hydrocarbons is liquid, clearly solubleand may be used directly in water as a concentrate; and further it isreadily thinned with water in proportions of 1:30 to 1:50 to give aviscous clear working solution. The product has particularly goodcutting fluid properties, that is, it is particularly good as alubricant coolant and leaves a smooth cut.

Example 16 Quantities of diethanolamine and boric acid, as described inExample 12, are dissolved when hot. Thereafter, 268 grams (2 mols) ofdiethyleneglycol monoethylether are added and heated as above described.After 50 minutes a temperature of 200 C. is reached. 216 ml. water aredistilled off. Then, as described, 560 gram (2 mols) of oleic acid areadded and, in a period of 20 minutes, 4 mols water are condensed olf ata temperature of between C. and 210 C. The resulting product is liquidand is an excellent emulsiier.

To form a concentrate, 50 parts of the resulting product are mixed with30 parts water and 20 parts hydrocarbon, as described in connection withExample 2. There is formed a clear, honey-yellow thin liquid which canbe further diluted with water to form working solutions, remains clear,and has excellent rust-inhibiting properties.

9 Example 17 Proceeding exactly as in Example 16 above, but instead ofdiethyleneglycol monoethylether, 236 grams (2 mols) of diethyleneglycolmonobutylether are used. A concentrate may be made as above described inconnection with Example 16.

Example 18 1,260 grams (12 mols) of diethanolamine are mixed with 244grams (4 mols) of boric acid, as described, an initial reactiontemperature is 130 C.; thereafter, the resulting mixture is heated to atemperature of 240 C. and 216 ml. water are condensed off. The reactionmixture is left to cool and, when at 180 C., a mixture of 280 grams (1mol) of oleic acid, and 320 grams (2 mols) of diethyleneglycolmonobutylether, are added. The combined reaction mixture is heatedagain. The reaction starts at about 250 C. The reaction temperature iskept during a period of time of about 11/2 hours at 220 C. by regulatingthe heating. In this period, 125 g. water (7 mols) are condensed olf.

The product is liquid and clearly soluble in water, and in this formprovides an excellent cooling and cutting uid concentrate.

Other glycols which, by experiment, have been tested for suitabilityare: ethyleneglycol mono isopropylether, ethyleneglycol mono butylether,ethyleneglycol mono ethylether, dieth-yleneglycol mono ethylether,trioxypropane, sorbtol.

The characteristics of the reaction products obtained according to theexamples above will now be described, with reference to the accompanyingdrawings in which:

FIG. 1 is a family of titration curves in which the ordinate representspH values and the abscissa 0.1 normal hydrochloric acid;

FIG. 2 is `an illustration of a testing apparatus to test broad arealubricating eiectiveness; and

FIGS. 3 and 4 are tables explaining experimental results.

The compositions of the present invention have substantial bufferingaction7 and may be referred to as broad spectrum buffers. They aredistinguished from known mixtures of buffering agents in that they donot cause precipitates with calcium-containing water even in a onepercent water solution. With a pH range between 9 and 7, they are stillcapable of capturing 21 milliliters of 0.1 normal hydrochloric acid, asshown by titration curve A1 of FIG. 1. A different product, the formulaof which is indicated in FIG. 1 of the drawing with respect to curve C,having molecular proportions of 2:1 of triethanolamine and boric acidsalts could capture only 13.5 milliliters of N/ 10 hydrochloric acid.

Referring again to the curves of FIG. 1, and particularly to titrationcurve B: a desired reaction product obtained in accordance with FormulaII of the boric acid salt of the 1,4-di-beta-hydroxyethylpiperazine cancapture twelve milliliters of 0.1 normal hydrochloric acid at theneutral point of pH 7, or 0.1 normal of sodium h-ydroxide, without anychange in pH value. This is also seen by extreme position of the twotitration curves A and B. Titration curves C, D and E illustrate theresults achieved with different compounds, the composition of which isindicated on the right hand of FIG. 1.

In general it may be stated that the pH value of the solutions is below9, which is particularly important to prevent skin irritation. The rustinhibiting effect of the broad spectrum buffering substances of thepresent invention is conjoined with the buffering eiect itself, whichcan be shown by experiments to be described.

The corrosion inhibiting effect of boric acid triethanolarnine salts, ina molecular proportion of 2:1, is compared with the reaction productobtained in Example 1, as well as with boric acid salts of thel,4-di-betahydroxy ethylpiperazine.

Test conditions: milling machine chips of cast iron,

for example of 3.47 percent carbon, 2.33 percent silicon, 0.77 percentmanganese, 0.29 percent phosphorus and 0.116 percent sulphur areobtained by dry machining. The chips are approximately 5-7 mm. long andhave a thickness of about 1 mm. A small heap of about 40 mm. (1.6inches) diameter and about 8-10 mm. high is placed on a watch glass ofabout 1() cm. (4 inches) diameter.

A solution of the substance to be tested, in distilled water, isprepared and poured over the heap of the chips so that the chips arecompletely wetted. Thereafter, excess solution is poured olf by tiltingthe watch glass, so that only so much of the solution remains as iscoated on the chips. -T his little heap of chips is left alone at atemperature of about 18 to 20 C. and in ordinary humidity of to 60percent. The test for rusting is done by rst considering the aspect ofthe chips from the top, to determine if there has been any rustformation; if there is then Table I (FIG. 3) will indicate Yes; if notthen No. If no rust is formed, a further inspection is done by observingthe chips from below, through the watch glass and making the followingdetermination:

No rust-No.

Below 5 spots-Minimal.

Below 25 spotsSmall.

About 25 spots-Yes.

Table I (FIG. 3) clearly shows that the corrosion inhibiting eifect ofthe products to be compared is parallel with the buifering effectdescribed in connection with the curve of FIG. 1. Substance No. 3 (rstcolumn Table I) is the reaction product obtained in Example I; this doesnot show any rust formation even in a dilution of 1 percent with a pI-Ibelow 9. Rusting occurs even at the 4 percent solution oftriethanolamine and boric acid, when the pH value of 9 is exceeded. Eventhe 1,4-di-beta-hydroxyethylpiperazine, although it has a lower pHvalue, has a better corrosion inhibiting eifect than triethanolamine,which is particularly apparent when the acid salts of the bases withboric acid are compared, that is the results of Substances Nos. 4 and 8of Table I. The substances, which are compared, have an alkaline N-atomcorresponding to one each acidic boron atom. In spite of the lower pHvalue, the use of l,4-dibetahydroxyethyl piperazine salts improves therust inhibiting eifect (Substance No. 8).

The unusual character of a reaction product such as that obtained inExample I is indicated by titration curve A in FIG. 1. It is seen thatthe titration curve does not change, even when the solution has beenyboiled for two hours. If the product would hydrolyze, then titrationcurve A would change to have the shape of titration curve B, which showsthe behaviour of a watery solution, of equal percentage contents, ofdiethanolamine and boric acid (mol proportion 2: l). This, however, isnot the case. The reaction product of Example I is saponified only byvery strong acids, for example smoking hydrochloric acid. If thereaction conditions are properly arranged, boric acid can be obtainedagain practically quantitatively in cnystalline form. This method can beused in order to determine the boric acid content in the compound.

The substances of the present invention have desirable biologicalcharacteristics; they are bacteriostatic, and fungicidal, when in theconcentration under which they would normally be used; but when dilutedsubstantially with water, they become bacteria-degradable.

Tapping fluids, based on mineral oils, may cause dermatalogicalirritations, for example causing oil-acne (LE. Dalton, J. AmericanMedical Association, 1951, pages 147 et seq.; and W. Morris and C. M.Maloof, New England Medical Journal, 1952, pages 247 and 440). Besidesthe oil itself, additives often added to oil base cutting fluids causeadditional irritation; such additives may be alkaline soaps, petroleumsulfonates, or other emulsiiers to make the mineral oil products wateremulsiiiable or water soluble. Experiments have shown, that the reactionproducts of the examples given above, do not cause irritation to thehuman skin when diluted to the extent useful in the metal workingindustry. The experiments were made with persons working in theindustry, and who already were sensitized to metal working cuttingfluids. The following solutions were prepared:

(1) A l-percent solution according to Example 1;

(2) A l-percent solution according to Example 2;

(3) A 1-percent solution of pure 1,4-di-beta-hydroxyethylpiperazine madeaccording to Examples l and ll.

Small patches were applied to the skin of the persons testing thematerial; the patches were permitted to remain for 24 hours. The testvolunteers, before having the patches applied, were subject to thefollowing dermatological diseases; dermatitis; eczema; mycotic eczemaand infective eczema; sporyasis; lichen ruber and pityriasis rosea.

After 24 hours, no reaction was noted in any one of the patches; noirritation to the skin under the patches could be determined.

Bacteriostatic effects Cooling lfluids prepared on the basis of emulsiedhydrocarbons are particularly subject to bacterial attack, which occurprimarily in the form of anaerobic bacteria, which attack the sulfonegroups of the emulsifiers. These sulfone groups are reduced andpoisonous, foul smelling hydrogen sulfide is liberated. This also, ofcourse, de composes the cooling oil. In order to prevent decomposition,air can be bubbled through the solution continuously, or bufferingadditives may be used. The use of additives, or air, is costly. Incontrast, the reaction products of the present invention do not containany sulfur, or sulfur compounds, and thus such anaerobic bacteria do nothave any medium to grow on. Reaction products of the present inventionhave bacteriocidal, fungicidal and insect repellant (and to some extentinsecticidal) properties; they are effective against gram-positive, aswell as against gram-negative bacteria. They inhibit the growth ofbacteria, as well as parasitic fungi, and are repellants for the carrierof these bacteria and fungi, mainly insects and particularly flies. Thebacteriocidal, fungicidal and insecticidal properties are obtainedwithout the addition of chemical compounds usually used for suchpurposes, such as halogens, phosphorus, or metal-containing compounds.

Experimental basis for tests for bacteriocidal effect A growing mediumof blood agar is infected with bacteria, as listed below, by applyingthereon small bits of filter paper, of about 9 mm. diameter. The growingmedium was left for 24 hours at 30 C. The test solution was preparedaccording to Example 2.

Dilution of reaction Results Product according to Example 2Staphylococcus Bacterium Prodgiosum (Gram-positive) (Gram-negative)Effective Inhibition..." Effective Inhibition. 17 do Do. 1/l0% LittleInhibition Little Inhibition.

TABLE II Percent dilution of Limit of Growth The dilution limit at whichgrowth still occurs is less than with bacteria, namely at between 0.02and 0.01 of the concentrate.

It has been found that concentrations of the reaction product down to0.5% have insecticidal effect, and at even greater dilutions thereaction product still acts as an insect repellent. Thus, the carriersof disease and irritation, particularly flies, are not attracted -toequipment utilizing a cooling fluid according to the present invention.The data of Table II, and the experiments show that a reactive productof the present invention, without any additives :used in theinsecticidal or fungicidal field, and without any poisons, inherentlyhas bacteriocidal, fungicidal and insecticidal effects when used in theconcentrations best suited for `metal working, for example, as a cuttingfluid. When the substance is, however, diluted, as for example in asettling tank, or in a disposal system, that is when it is present inconcentrations below 0.02%, and for example 0.001%, if not only losesall its bacteriocidal effects, but on the contrary becomesbacteriologically degradable. It thus can be disposed of without causingpollution of rivers, lakes, or waterways.

Metal-workin g utility For practical use as a cooling lubricating anddetergent concentrate for use in the metal working industry, for exampleas a cutting fluid, as a fluid for use in lubrication for rolling ordrawing of sheet, or wire, for lathe turning, drilling and boring,tapping, and grinding, a concentrate of reaction product is diluted withwater. The separate machines are preferably supplied from a centralstorage system, as is well known in the art, in which the properdilution for the use of the machinery can be maintained. It has beenfound that, as cutting fluids, for example for use in a lathe, thereaction products of the present invention made according to the aboveExamples 2 to l1, are best utilized in a concentration which is above0.1% and preferably in a region of from 1 to 3% of the substance, withthe remainder water. The high degree of dilution of the cencentratepermits efficient utilization of the cutting fluid.

yIn order to test the lubricating effectiveness, various lubricationtests have been devised. Since the reaction products of the presentinvention are particularly useful in lathe cutting and grinding, wherethe contact of the tool with the work piece is not ordinarily along apoint but rather over a broader area, for example ideally a line, a testapparatus to test lubricating effectiveness under simulated conditionsis described. Reference may also be had to Schmiertechnik No. 4, pages184-191; 1956, article by Bartel et al.

Referring now to PIG. 2: a test bolt 6 is inserted into a holding ring4. Test bolt 6 is supported within the holding ring 4 on a pair offlattened pins 5, which are held against rotation within the holdingring 4. The test bolt 6 is arranged to be rotated, Holding ring 4, withits pins 5, is suspended by means of a steel band 1 from a holder 10.The relative pressure of pins 5 against the test bolt 6 can be adjustedas indicated schematically by arrows 2, 20. Holding ring 4 is providedwith a lever 8, which bears against a scale schematically indicated at9.

The suspension by steel band 1 is such that the pins 5 are exactlyparallel to the axis of test bolt 6. The test bolt is made a carbonsteel C-15, with about 0.1 micron roughness; it may have a diameter ofabout an inch and a hardness of 63 Rockwell. The pins 5 are offset 45from either side of a vertical center line; the pressure of the pinsagainst the test bolt, that is the forces schematically indicated byarrows 2, 20, are about 4,500 kg./cm.2; the relative speed 0.2 meter/per sec. (for a l-inch test bolt, this corresponds to a speed of about150 r.p.m.).

At the beginning of the test, a pure line contact is obtained betweenthe pins and the test bolt. The test is carried out for a period ofabout 3 hours. The sliding contacts between pins 5 and bolts 6 areflooded with lubricating-cooling substances. During the test, vibrationis considered; the friction at the beginning (nA) and at the end (aE) ismeasured. The temperature at the test stand at the beginning (TA) and atthe end (TE) of the test is determined. After the test, the track madeby the pins 5 is inspected.

If the surface is smooth and does not show any groove, then thelubricating efectiveness is good. A decreasing sliding friction (,uE/LA) shows a good lubricating film. Comparison of the temperature at thebeginning and at the end of the experiment indicates the coolingeffectiveness. The temperature difference should -be small.

The data of Table III, FIG. 4, show the results of the test, andcomparison with known cooling iluids. Table III, FIG. 4, showsdecreasing sliding friction, which is further indicated by the smalldegree of wear and the good aspect of the track made by the pins 5.Mineral oil based cutting oils, activated by additives, are initiallybetter lubricants; but the much higher degree of heating, due to thesmaller thermal capacity and cooling effectiveness of oils alsodecreases lubricating eiciency. In actual machining operation, heatingof tools causes dulling and increases the necessity for resharpening.

The commercial cutting uid of Table III (FIG. 4) item 2, is a waterdispersable fluid in which the dilution of l to 40 is the limit of therecommended use; the lubricating eiectiveness at this dilution isalready impaired.

The present invention thus provides reaction products which areWater-soluble, water-emulsiable and dispersable. They are corrosioninhibiting and useful as `a cutting fluid in a metal working eld, theycombine the advantages of high lubricating eiectiveness and corrosioninhibition of the mineral oil base cutting fluids with the high coolingeiciency of the water base cutting uids. They do not have any of thedisadvantages of either, however, namely, subject to decomposition or anecessity for poisonous additives. Additionally, the reaction productsof the present invention provide cutting uids which are bacteriostatic,and yet biologically degradable so that they can be disposed of readilyWithout causing pollution. When used as detergents, the reactionproducts have excellent cleaning properties and are efficient emulsiersand buffering agents. The property of biologic degradability, thusproviding for ease of disposal, likewise obtains when they are used asdetergents.

I claim:

1. A boronand nitrogen-containing reaction product is formed by:

reacting at least two molar proportions of a secondary aliphaticaminoalcohol with one molar proportion of a boron-containing compoundselected from the group consisting of boric acid, HBO2, H2B4Oq and B203,at a temperature from about C. to about 230 C., and removing Water ofreaction as it forms, whereby a boronand nitrogen-containing reactionproduct is obtained.

2. Process for the production of a boronand nitrogen-containing reactionproduct comprising:

reacting at least two molar proportions of a secondary aliphaticaminoalcohol with one molar proportion of a boroncontaining compoundselected from the group consisting of boric acid, H1302, H2B4O7, andB203, at a temperature from about 130 C. to about 230 C., and removingWater of reaction as it forms, whereby a boronand nitrogen-containingreaction product is obtained.

References Cited UNITED STATES PATENTS 2,441,063 5/1948 Gilmann 260-462X 2,408,332 9/1946 Morgan 260-462 X CHARLES B. PARKER, Primary Examiner.

R. L. RAYMOND, Assistant Examiner.

U.S. C1. X.R.

